This invention relates to a wiring circuit substrate that carries a great number of pairs of circuit elements packaged by resin molding or the like on the both sides of the wiring substrate, which provides a matrix electrode driving circuit of high degrees by giving symmetry and regularity on an arrangement of the circuit elements, and to a manufacturing process of the above wiring circuit substrate.
When a display device including display elements formed by X-Y matrix electrodes such as a thin film EL display device is driven, driving circuits are necessary comprising of a number of the electrodes. For example, in a display device having X electrodes of 240 lines and Y electrodes of 320 lines, the driving circuits at an amount of 560 circuits are necessary. Accordingly, in order to dispose so electrodes and many driving circuits, various devices of the driving circuit and packaging methods of circuit elements have been offered.
FIG. 1 is a block diagram of an peripheral circuit of a conventional thin film EL display device.
In the case where a display device 1 having X-Y matrix electrodes 16, is driven, the display device 1 must comprise electrode driving circuits 2 and 3 corresponding to each of the matrix electrodes, and logic circuits (serial-parallel conversion transmitters 6 and 7, memory circuits 5 and gate circuits 4, etc.).
Further, more wiring for connecting one of the logic circuits to another of the logic circuits, and one of the logic circuits to one of the electrodes of the matrix electrodes, is required.
The number of wirings for transmitting signals from data circuits 8 and 9 and a controller 10 to the serial-parallel conversion transmitor 6 is required to be several, and the wirings between the logic circuits are formed in an integrated circuit because the logics are formed on the substrate such as a ceramic substrate or the like.
In the electrode driving circuit, a drain of every high voltage driving transistors 11 is connected to a cathode of every diode as shown in FIG. 2, and a high voltage is outputted from the intersection between the drain of the high voltage driving transistor and the cathode of the diode.
When the electrode driving circuit is provided with a high voltage driving IC (integrated circuit) 13 including the high voltage transistors 11, and a high voltage driving diode array 14, intersections are formed between the drain of the transistors 11 and the cathode of diodes 12. Accordingly, a hybrid driving circuit, which is prepared with several sets of a high voltage driving IC and a high voltage driving diode array on a small substrate, which locates the wirings in the substrate, has been offered.
According to the above hybrid driving circuit, complex circuits are disposed on the same substrate, and this substrate is provided on a mother board such as a flexible substrate or the like. The number of output wirings correspond to that of input wirings of the matrix electrodes.
The above proposal has not improved the wirings of the high voltage driving transistors and the high voltage driving diodes.
Because both an IC including the high voltage transistors and the high voltage driving diodes are wired by thick films or the like, a great number of wirings are required for connecting the IC to the diodes. Further, the devices have low productivity and are expensive because of the high density formed by the small wirings. An additional space for the diode itself and the space of the wirings between the cathode of the diode and the transistor is required.
It is an object of the present invention to provide a wiring circuit substrate carrying a great number of pairs of circuit elements packaged by resin mold or the like on the both sides of the wiring substrate, which provides a matrix electrode driving circuit of high degrees by giving symmetry and regularity on an arrangement of the circuit elements.
It is another object to provide a manufacturing process of the above wiring circuit substrate.
It is a further object of the present invention to provide a new circuit substrate which is able to be smaller, lighter and lower in cost to form a display device having a matrix electrode.
According to the present invention, a circuit element including the pairing of a diode and a transistor can be arranged for each electrode line of the X-Y matrix electrodes, and the present invention can achieve not only a high density package with small wirings, but also high productivity.
Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. It should be understood, however, that the detailed description of, and specific examples, while indicating preferred embodiments of the invention are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
According to an embodiment of the present invention, a wiring circuit substrate comprises first circuit element means on one side of the substrate connected to electrode lines of X-Y matrix electrodes respectively, and second circuit element means in the symmetrical position of the first circuit element means on the other side of the substrate connected to the electrode lines of the X-Y matrix electrodes, respectively, wherein each of the leads of the first and the second circuit element means is connected output and input lines of the X-Y matrix electrodes via through holes, respectively.
The first circuit element means comprises integrated transistors for driving the X-Y matrix electrodes. The second circuit element means comprises integrated diodes for protecting an overcurrent in the X-Y matrix electrodes.
According to an embodiment of the present invention, a manufacturing method of an integrated circuit substrate comprises the steps of arranging temporarily in a symmetrical position on both sides of the substrate first circuit element means and second circuit element means which are to be connected to electrode lines of X-Y matrix electrodes, respectively, pressing and heating for connecting the leads of the first circuit element means and second circuit element means, connecting a pair of the connecting leads of the first circuit element means and the second circuit element means on the both sides of the substrate, translating the substrate to carry the new first and second circuit means after the previous first and the second circuit element element means are adhered to the substrate.